Ecological safety analysis model construction method by introducing foreign organisms into ballast water

Abstract

The invention discloses a method for constructing an analysis model for ecological safety by introducing foreign organisms into ballast water, and relates to the technical field of ecological safety, the method comprises the following steps: S1, selecting a target species, and selecting target organisms suitable for a local environment based on typical invasive organisms listed by global ballast water management projects; s2, determining indexes of pressure, state and response of the PSR model, and filling the indexes into a PSR model framework to obtain an ecological safety analysis model; s3, carrying out weight assignment on the indexes by adopting an analytic hierarchy process, and comparing the importance of each index through scoring; s4, giving objective weights to the indexes by using an entropy weight method, standardizing the indexes in combination with historical data, and calculating information entropy; s5, the weight of each index is synthesized through a combination weighting method, and the scientificity of weight distribution is ensured in combination with scoring and objective data; and S6, calculating an ecological safety state based on the combined weight, and dividing safety levels according to the ecological comprehensive evaluation index.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological safety, and in particular to a method for constructing an analysis model of the impact of the introduction of alien organisms into ballast water on ecological safety. Background Art

[0002] With the rapid development of global trade, ship ballast water has become an important channel and carrier for the invasion of alien marine organisms. Every year, more than 12 billion tons of ballast water are carried by ships around the world, allowing biological populations in different ecosystems to cross geographical isolation and come to another ecological environment. Once these biological populations survive in another ecological environment and form dominant species, they will cause the invasion of alien species. According to data from the International Council for the Exploration of the Sea (ICES), 94% of potentially harmful marine organisms are spread through ship ballast water. Invasive organisms will disrupt local ecosystems, affect biodiversity, and cause huge economic losses. The discharge of ballast water from international ships has attracted the attention of various countries and has been listed as one of the "four major hazards" facing the ocean by the United Nations Global Environment Fund (GEF). my country is a major maritime country, and the frequent economic and trade exchanges with foreign countries have increased the risk of invasion by alien marine organisms in my country. The invasion of marine organisms in my country shows a trend of increasing number, faster frequency of introduction, wider spread, more severe harm and more severe economic losses, which has had a serious impact on my country's offshore ecological environment and ecological security. It is necessary to sort out the relevant factors that affect the occurrence of offshore ecological disasters and the relationship between their invasion disaster process and offshore ecological environmental safety in order to take appropriate response measures.

[0003] At present, there are few studies on the process of invasion disasters caused by alien organisms carried by ballast water, which are relatively general and scattered, mainly staying at literature research and qualitative analysis, and most of them are references and citations of existing foreign indicator systems, as well as adaptive modifications for application objects. The construction of a localized indicator system for the characteristics of my country's coastal ecosystems is still in the exploratory stage, and the theory, methods and verification research of marine ecosystem health assessment still need to be further improved and developed. Summary of the invention

[0004] The purpose of the present invention is to provide a method for constructing an analysis model of the impact of the introduction of alien organisms into ballast water on ecological safety, so as to meet the requirements for the prevention and control of alien organisms in ballast water.

[0005] The technical solution of the present invention is to provide a method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water, the method comprising:

[0006] S1. Select target species. Based on the typical invasive organisms listed by the Global Ballast Water Management Program, select target organisms (organisms that are suitable for the local environment);

[0007] S2. Establish the indicators of the three categories of pressure, state and response of the PSR model, fill them into the PSR model framework, and obtain the ecological security analysis model;

[0008] S3, use the hierarchical analysis method to assign weights to the indicators and compare the importance of each indicator by scoring;

[0009] S4. Use the entropy weight method to assign objective weights to indicators, standardize each indicator based on historical data, and calculate information entropy;

[0010] S5. The weights of each indicator are synthesized through the combined weighting method, and the scientific nature of the weight distribution is ensured by combining expert scores and objective data;

[0011] S6. Calculate the ecological security status based on the combined weights and divide the security levels according to the comprehensive ecological evaluation index.

[0012] In any of the above technical solutions, further, step S3 specifically includes:

[0013] Score the importance of each indicator relative to another indicator. The score range is 1-9. The higher the value, the more important it is. After scoring, calculate the average score of each indicator. i,j Indicates the evaluation index S i Relative to the evaluation index S j The importance average of the final scoring results is combined into the following comparison matrix B:

[0014]

[0015] Among them, the score S i,j The average importance of i=j is set to 1;

[0016] Then calculate the eigenvector of the above matrix and normalize the eigenvector to obtain the weight vector ω of each indicator i =(ω1,ω2,…,ω n ),ω n is the weight corresponding to the evaluation index n;

[0017] After the weights are obtained, a consistency check is performed. If the consistency ratio (CR) is less than or equal to 0.1, the consistency check of the matrix passes, indicating that the scoring result is credible. The formula is as follows:

[0018]

[0019] Among them, CI is the consistency index, RI is the random consistency index, and the CI calculation formula is:

[0020]

[0021] where λ max It is the maximum eigenvalue of the matrix. If CR≤0.1, the consistency test is passed and the subjective weight of each indicator is finally confirmed.

[0022] In any of the above technical solutions, further, step S4 specifically includes:

[0023] S41. Collect several years of ocean-related data as analysis samples and correspond them to the indicators of the analysis model;

[0024] S42. Data standardization: First, the data of each indicator is standardized to ensure that the indicator data of different units and ranges can be compared with each other; the standardization formula is as follows:

[0025]

[0026] Among them, X ij represents the value of the jth sample on the i-th index; Y ij is the standardized value;

[0027] S43. Calculate information entropy: Information entropy is used to measure the uncertainty of indicators and calculate the standardized data Y ij The probability distribution formula is:

[0028]

[0029] According to the definition of information entropy, the information entropy E of index i i The calculation formula is:

[0030]

[0031] Among them, if P ij =0, then define

[0032] S44. Determine the weight of each indicator: Calculate the weight of each indicator based on information entropy. The smaller the information entropy, the greater the amount of information in the indicator, so its weight should be higher. The formula for calculating the weight is:

[0033]

[0034] Among them, W i is the objective weight of each indicator using the entropy weight method.

[0035] In any of the above technical solutions, further, the calculation formula of the combined weighting method in step S5 is:

[0036]

[0037] Among them, K iis the combined weight, ω i is the subjective weight calculated in step S3, W i is the objective weight calculated in step S4.

[0038] In any of the above technical solutions, further, the target species is Karenia mikimotoi, a toxic algae that is prone to cause red tide disasters and is suitable for assessing local ecological safety.

[0039] In any of the above technical solutions, further, the indicators of the three categories of pressure, state and response in the model obtained in step S2 include:

[0040] The pressure indicators include: the number of foreign trade ships entering and leaving the port, the throughput of foreign trade goods, the population density of coastal cities, the amount of industrial wastewater discharged into the sea, the area of ​​serious pollution in the entire sea area, the number of red tide disasters, and the area of ​​red tide disasters, a total of 7 negative indicators;

[0041] The status indicators include: active phosphate, inorganic nitrogen, temperature, salinity, suspended solids, phytoplankton diversity index, zooplankton diversity index, benthic animal diversity index and ecosystem health status, a total of 9 positive indicators;

[0042] The response indicators include: joining the Ballast Water Convention, the Bohai Sea Comprehensive Management Action Plan, the number of marine and coastal nature reserves, the establishment of a red tide monitoring and early warning system, industrial wastewater discharge management and fishery resource restoration and protection, a total of 6 positive indicators.

[0043] The beneficial effects of the present invention are:

[0044] The technical solution in the present invention is based on the pressure-state-response (PSR) model, which systematically considers the impact of human activities (such as ship ballast water discharge) on offshore ecosystems, and constructs an ecological security analysis system with 22 indicators, which can comprehensively reflect the current status and potential risks of ecological security.

[0045] The weight assignment method that combines the analytic hierarchy process (AHP) and the entropy weight method takes into account the subjectivity of scoring and the objectivity of data, ensures the scientific rationality of the indicator weight allocation, and enables the model to more accurately quantify the impact of various factors on ecological security.

[0046] In a preferred implementation of the present invention, the method selects Karenia mikimotoi as the target species and constructs a localized indicator system in combination with the ecological characteristics of my country's offshore waters, which facilitates practical application in my country's coastal environment and enhances the applicability and pertinence of the model.

[0047] The model provided by the present invention can classify offshore ecological security into different levels, and provide clear security level indicators for relevant management departments, so that decision makers can take corresponding measures according to different levels, thereby effectively preventing and controlling the invasion of alien species. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The advantages of the above and additional aspects of the present invention will become apparent and easily understood in the description of the embodiments in conjunction with the following drawings, in which:

[0049] Figure 1 is a flowchart of the steps of a method for constructing an analysis model of ecological safety of ballast water introduced with foreign organisms according to an embodiment of the present invention;

[0050] Figure 2 : is a PSR model structure diagram of a method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water according to an embodiment of the present invention;

[0051] Figure 3 It is a schematic diagram of analyzing the safety of offshore ecological environment according to a method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0053] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0054] like Figure 1As shown, this embodiment provides a method for constructing an analytical model of ecological security caused by the introduction of alien organisms into ballast water. The analytical model can describe the invasion disaster process caused by alien organisms carried by ship ballast water in the offshore environment, and analyze the threat of such invasion to ecological security. Through this model, the biological risks brought by ballast water can be effectively quantified and tracked, helping decision makers to grasp the current ecological security situation and take corresponding policy measures for prevention and control. The analytical model is constructed based on the PSR model. The PSR model is an evaluation structure containing three elements. It is a systematic framework for environmental monitoring and management. It decomposes and organizes the cause-effect relationship in the environmental system to more clearly quantify environmental problems and guide decision makers to take effective response measures. It is decomposed into three main levels for clearer understanding and monitoring. The three elements are: Pressure, the negative impact of human activities (such as ship transportation) on the marine environment; State, the health status of the marine environment, covering various ecological indicators; Response, the efforts made by humans to improve or restore the environment.

[0055] The analysis model building method includes:

[0056] S1. Select target species suitable for analysis. Based on the main global distribution of ten typical invasive organisms carried by ballast water listed by the Global Ballast Water Management Project (IMO Globallast), Karenina mikimotoi, which is suitable for the local environment, was selected as the target organism for research.

[0057] Karenia mikimotoi is a toxic algae and one of the main invasive species in my country's coastal areas, which can cause red tide disasters.

[0058] S2, such as Figure 2 As shown in the figure, based on the PSR model, an analysis model for the impact of alien organisms introduced into ballast water on ecological security is constructed, including 22 basic indicators in three categories: pressure, state, and response.

[0059] Among them, the pressure index represents the impact that humans have on the environment for their own survival and development, etc., reflecting the negative impact of human activities, especially ocean shipping, on offshore ecological security. In this embodiment, there are a total of 7 pressure indicators.

[0060] The status index refers to the carrying capacity status of the offshore ecosystem itself, indicating the services and functions provided by the offshore waters to humans, such as the species status and functional status of the offshore ecosystem. In this embodiment, there are 9 indicators in total.

[0061] The response index is the defense of human beings' subjective initiative in environment, social economy and policy. It reflects people's efforts to maintain the safety of offshore ecological environment and reduce the invasion of alien species. It is a positive indicator. In this embodiment, there are 6 of them.

[0062] There are 22 indicators in three categories: pressure, state, and response, and their attributes are shown in Table 1:

[0063] Table 1

[0064]

[0065]

[0066] In the PSR model, the logic of the three categories of pressure, state and response affecting each other is as follows:

[0067] As human activities intensify, the value of the pressure indicator increases, the value of the state indicator decreases, and the pressure has a negative effect on the state; as the ecology deteriorates, the value of the state indicator decreases to a certain value, the value of the response indicator increases, and the state triggers the response; when humans take measures to protect the environment, the value of the response indicator increases, the value of the pressure indicator decreases, and the response regulates the pressure.

[0068] S3. After determining the above model parameters, since the importance of each indicator to the whole is different, the analytic hierarchy process AHP is used to assign weights to each indicator according to its importance in the model:

[0069] The relative importance of indicators of the same level was compared by expert scoring. 20 experts in the fields of ships, environmental protection, and inspection and quarantine were convened to score the importance of each indicator relative to another indicator. The score range was 1-9, and the higher the value, the more important it was. After scoring, the average score of each indicator was calculated. i,j Indicates the evaluation index S i Relative to the evaluation index S j The importance average of the final scoring results is combined into the following comparison matrix B:

[0070]

[0071] Among them, the score S i,j The average importance value of i=j is set to 1.

[0072] Then calculate the eigenvector of the above matrix and normalize the eigenvector to obtain the weight vector ω of each indicator i =(ω1,ω2,…,ω n ),ω n is the weight corresponding to the evaluation index n;

[0073] After the weights are obtained, a consistency check is performed. If the consistency ratio (CR) is less than or equal to 0.1, the consistency check of the matrix passes, indicating that the scoring result is credible. The formula is as follows:

[0074]

[0075] Among them, CI is the consistency index, RI is the random consistency index, and the CI calculation formula is:

[0076]

[0077] where λ max It is the maximum eigenvalue of the matrix. If CR≤0.1, the consistency test is passed and the subjective weight of each indicator is finally confirmed.

[0078] S4. In order to increase the objectivity of weight distribution, the entropy weight method is used to objectively assign weights to each indicator. The specific operation is as follows:

[0079] S41. Collect several years of ocean-related data as analysis samples and correspond them to the various indicators of the analysis model.

[0080] S42. Data standardization: First, the data of each indicator is standardized to ensure that the indicator data of different units and ranges can be compared with each other; the standardization formula is as follows:

[0081]

[0082] Among them, X ij represents the value of the jth sample on the i-th index; Y ij is the standardized value.

[0083] S43. Calculate information entropy: Information entropy is used to measure the uncertainty of indicators and calculate the standardized data Y ij The probability distribution formula is:

[0084]

[0085] According to the definition of information entropy, the information entropy E of index i i The calculation formula is:

[0086]

[0087] Among them, if P ij =0, then define

[0088] S44. Determine the weight of each indicator: Calculate the weight of each indicator based on information entropy. The smaller the information entropy, the greater the amount of information in the indicator, so its weight should be higher. The formula for calculating the weight is:

[0089]

[0090] Among them, W iis the objective weight of each indicator using the entropy weight method.

[0091] S5, the weights obtained by the analytic hierarchy process in step S3 and the entropy weight method in step S4 are combined and weighted to obtain a combined weight, the combined weight K i The calculation method is:

[0092]

[0093] In this way, the expert's experience and knowledge and objective data statistics are taken into consideration to ensure the scientificity and rationality of the weight distribution.

[0094] S6. After obtaining the combined weight of each indicator, the safety status of the offshore ecological environment can be graded. According to the ecological comprehensive evaluation index calculated by the combined weight, the safety level is divided into five levels (the higher the level, the less safe), and the standard range of each level is shown in Table 2 below:

[0095] Table 2

[0096]

[0097] like Figure 3 As shown, in another embodiment of the present invention, the data obtained from the Ecological Environment Bulletin from 2011 to 2020 are used to analyze the offshore ecological environment security. It can be seen that although my country's offshore ecological environment security is on the rise, it is generally in a general state.

[0098] In summary, the present invention proposes a method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water, comprising:

[0099] S1. Select target species based on the typical invasive organisms listed in the Global Ballast Water Management Program and select target organisms suitable for the local environment.

[0100] S2. Establish the indicators of the three categories of pressure, state and response of the PSR model, fill them into the PSR model framework, and obtain the ecological security analysis model.

[0101] S3. Use the analytic hierarchy process to assign weights to the indicators and compare the importance of each indicator through expert scoring.

[0102] S4. Use the entropy weight method to assign objective weights to indicators, standardize each indicator based on historical data, and calculate information entropy.

[0103] S5. The weights of each indicator are synthesized through the combined weighting method, and the expert scores and objective data are combined to ensure the scientific nature of the weight distribution.

[0104] S6. Calculate the ecological security status based on the combined weights and divide the security levels according to the comprehensive ecological evaluation index.

[0105] The steps in the present invention can be adjusted in order, combined or deleted according to actual needs.

[0106] The units in the device of the present invention can be combined, divided and deleted according to actual needs.

[0107] Although the present invention is disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and are not intended to limit the application of the present invention. The scope of protection of the present invention is defined by the appended claims and may include various modifications, alterations and equivalents made to the invention without departing from the scope and spirit of the present invention.

Claims

1. A method for constructing an analysis model of the impact of the introduction of foreign organisms into ballast water on ecological safety, characterized in that: The method comprises: S1. Select target species based on typical invasive organisms listed in the Global Ballast Water Management Program; S2. Establish the indicators of the three categories of pressure, state and response of the PSR model, fill them into the PSR model framework, and obtain the ecological security analysis model; S3, use the hierarchical analysis method to assign weights to the indicators and compare the importance of each indicator by scoring; S4. Use the entropy weight method to assign objective weights to indicators, standardize each indicator based on historical data, and calculate information entropy; S5. The weights of each indicator are synthesized through the combined weighting method, and the scoring and objective data are combined to ensure the scientific nature of the weight allocation; S6. Calculate the ecological security status based on the combined weights and divide the security levels according to the comprehensive ecological evaluation index.

2. The method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water according to claim 1, characterized in that: The step S3 specifically includes: Score the importance of each indicator relative to another indicator. The score range is 1-9. The higher the value, the more important it is. After scoring, calculate the average score of each indicator. i,j Indicates the evaluation index S i Relative to the evaluation index S j The importance average of the final scoring results is combined into the following comparison matrix B: Among them, the score S i,j The average importance of i=j is set to 1; Then calculate the eigenvector of the above matrix and normalize the eigenvector to obtain the weight vector ω of each indicator i =(ω1,ω2,…,ω n ),ω n is the weight corresponding to the evaluation index n; After the weights are obtained, a consistency check is performed. If the consistency ratio (CR) is less than or equal to 0.1, the consistency check of the matrix passes, indicating that the scoring result is credible. The formula is as follows: Among them, CI is the consistency index, RI is the random consistency index, and the CI calculation formula is: where λ max It is the maximum eigenvalue of the matrix. If CR≤0.1, the consistency test is passed and the subjective weight of each indicator is finally confirmed.

3. The method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water according to claim 1, characterized in that: The step S4 specifically includes: S41. Collect several years of ocean-related data as analysis samples and correspond them to the indicators of the analysis model; S42. Data standardization: First, the data of each indicator is standardized to ensure that the indicator data of different units and ranges can be compared with each other; the standardization formula is as follows: Among them, X ij represents the value of the jth sample on the i-th index; Y ij is the standardized value; S43. Calculate information entropy: Information entropy is used to measure the uncertainty of indicators and calculate the standardized data Y ij The probability distribution formula is: According to the definition of information entropy, the information entropy E of index i i The calculation formula is: Among them, if P ij =0, then define S44. Determine the weight of each indicator: Calculate the weight of each indicator based on information entropy. The smaller the information entropy, the greater the amount of information of the indicator, so its weight should be higher. The formula for calculating the weight is: Among them, W i is the objective weight of each indicator using the entropy weight method.

4. The method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water according to claim 1, characterized in that: The calculation formula of the combined weighting method in step S5 is: Among them, K i is the combined weight, ω i is the subjective weight calculated in step S3, W i is the objective weight calculated in step S4.

5. The method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water according to claim 1, characterized in that: The target species is Karenia mikimotoi, a toxic algae that is prone to cause red tide disasters and is suitable for assessing local ecological safety.

6. The method for constructing an analysis model of ecological safety caused by the introduction of foreign organisms into ballast water according to claim 1, characterized in that: The indicators of the three categories of pressure, state and response in the model obtained in step S2 include: The pressure indicators include: the number of foreign trade ships entering and leaving the port, the throughput of foreign trade goods, the population density of coastal cities, the amount of industrial wastewater discharged into the sea, the area of ​​serious pollution in the entire sea area, the number of red tide disasters, and the area of ​​red tide disasters, a total of 7 negative indicators; The status indicators include: active phosphate, inorganic nitrogen, temperature, salinity, suspended solids, phytoplankton diversity index, zooplankton diversity index, benthic animal diversity index and ecosystem health status, a total of 9 positive indicators; The response indicators include: joining the Ballast Water Convention, the Bohai Sea Comprehensive Management Action Plan, the number of marine and coastal nature reserves, the establishment of a red tide monitoring and early warning system, industrial wastewater discharge management and fishery resource restoration and protection, a total of 6 positive indicators.

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